It doesn't seem like this is a one time thing. Apparently she and her friends drink frequently. That's worth telling your parents about I think, it's not like she's just trying it or anything.
we don't know anything because now OP showed up halfway through the thread to tell us that he THINKS his sister steals. like what does that tell you about anything here told to us by him. besides is it abuse of alcohol? we don't know, op doesn't know
Enforcing law =/= ruining someone's life, unless OP makes a big deal out of this (like if he gets the police involved)
Why are people saying "nothing"?
It's clearly illegal therefore OP should do something. Goodness, what has society come to? we're supporting illegal activities? seriously?
this "law > family" attitude needs to go out the window asap. idk if you guys suffer from some family dysfunction issue or whatever but its not welcome in the real world
anyways are you worried for her health? or that she is breaking a law here? im confused. because if its the latter, get out